To increase a network capacity, small-sized and densely deployed access points in a wireless network are a development trend of the wireless network. An ultra-dense network (Ultra-dense network, UDN) allows access of a user terminal from a place as near as possible, to increase a throughput of the user terminal and a regional throughput of a system.
Dense network deployment means that more wireless access points such as base stations need to be deployed in one coverage area. Consequently, many coverage areas overlap in a network, and a large quantity of user terminals are located in these overlapping areas. Application of a coordinated multipoint transmission/reception (Coordinated Multipoint transmission/reception, CoMP) technology thus becomes more necessary. Coordinated multipoint transmission/reception CoMP is a technology for improving cell edge spectrum efficiency and expanding data coverage. Selection of a coordinating set, transmission points (base stations participating in coordinated transmission/reception), and a coordinated transmission/reception mode determines performance of coordinated transmission/reception. There are two common coordinated multipoint transmission/reception technologies: joint transmission (Joint Transmission) and coordinated beamforming (Coordinated Beamforming). During application of the coordinated beamforming technology, cells participating in coordination need to share information about channels between a user terminal and all these cells. For the joint transmission technology, cells need to share not only channel information but also data information of a user terminal.
On the other hand, in a dense network, constrained by costs and other factors, not every wireless access point (for example, a base station) has an ideal backhaul. Due to the backhaul constraint, flexible use of access and backhaul resources exerts great impact on resource utilization and transmission performance of a system.
Conventionally, allocation of access and backhaul resources is fixed and based on a time domain, and is not adaptive to the dynamic nature of a dense network. In addition, the conventional allocation of access and backhaul resources does not take a data transmission mode of a user terminal into consideration. As a result, system resource utilization and transmission efficiency are decreased.
Therefore, how access and backhaul resources are properly allocated for a user terminal in a network becomes an extremely important problem that needs to be resolved urgently.